Frac diverter and method

ABSTRACT

A fracture diverter including a body having a porosity and permeability that allows the passage of fluid and not proppant and a set of dimensions selected to enter an expected dimension perforation.

BACKGROUND

In the resource recovery industry, fracturing operations have become essential to maximizing production capability from most wells. Fracturing uses high pressure fluid to fracture the formation surrounding a borehole to allow formation fluids an easier path to drain into the borehole. Fracturing works well for this purpose but it is known that sometimes the fracture paths are not evenly distributed along the wellbore since different rock formations and fluid frictional issues can cause certain areas of the wellbore to fracture first and then allow the fracture fluid to follow the path of least resistance into those fracture points and effectively skip over other perforations where additional fractures would otherwise further increase production from the well. The art has tried several types of technologies to divert the fracture fluid from least resistance pathways to higher resistance pathways but has had limited success. Sometimes the methods employed fail to divert fluid sufficiently to fracture recalcitrant perforations and sometimes the diverters themselves become an issue later in production since things such as steel balls may end up damaging other well systems.

SUMMARY

An embodiment of a fracture diverter including a body having a porosity and permeability that allows the passage of fluid and not proppant and a set of dimensions selected to enter an expected dimension perforation.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

FIG. 1 is a schematic elevation view of a wellbore system within which a fracture diverter is disposed as disclosed herein;

FIG. 2 is an enlarged view of a single perforation with a diverter body therein; and

FIG. 3 is the same view as FIG. 2 but with a diverter body positioned radially outwardly of the perforation.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

Referring to FIG. 1, a typical wellbore system 10 including a borehole 12 in a subsurface formation 14. The illustrated system 10 includes a string of casing 16 disposed in the borehole 12 and generally includes cement 18 between the string 16 and the borehole face 20. Perforations 22 are illustrated having been created using a perforation gun assembly that is not shown but well known in the art. Once the perforations are created, the fracturing operation begins with the application of high-pressure fracture fluid pumped down the borehole 12. As will be recognized by the ordinarily skilled artisan, high-pressure fluid tends to follow the path of least resistance. Accordingly, the first perforation to be associated with a relatively larger fracture in the formation 14, will tend to absorb the high-pressure flow and thereby reduce the chances of other perforations experiencing sufficient high-pressure to propagate a fracture into the formation. This also causes a loss of fracture fluids, which is expensive. In order to alleviate this problem, the inventor hereof has devised a fracture diverter 24. The diverter 24 comprises one or more bodies 26 combined with a fracture fluid 28 to be pumped into the borehole at high pressure. Precise pressures at which pumping takes place are known to the art. The body 26 comprises material having a sufficient porosity and permeability to pass fluid, while not allowing the passage of proppant through the body and a set of dimensions selected to facilitate entry to an expected dimension perforation for the well system in which the diverter is being used. Each of the properties recited work to achieve the benefit of the diverter hereof over those used in the prior art. The dimensions of the body 26 ensures the body will become jammed in the perforation 22. This may be due to the differential between the high pressure of fracturing such as 10,000 PSI versus the relatively lower pressure of production in the opposite direction, such as 1000 PSI. One will appreciate that forcing a body into a perforation 22 under 10,000 PSI (see FIG. 2) will tend to jam the body 26 into that perforation 22 with more permanence than the 1000 PSI production pressure that might otherwise work to expel the body 26 from the perforation 22. Tightly jamming the body 26 a into the perforation creates a significant impediment for the fracture fluid and hence causes the fracture fluid to seek other paths, thereby facilitating fracturing through other perforations 22. In an embodiment, the body 26 comprises an expanding material such as a shape memory material (e.g. a shape memory polymer foam such as the foam marketed under the tradename GeoFORM from Baker Hughes). Expanding materials in the FIG. 2 embodiment help the jamming energy. Expanding materials whether shape memory or simply a rebound (resilient material) from being compressed through the perforation 22 are also useful in an embodiment as shown in FIG. 3, wherein the body 26 b is forced all the way through the perforation 22 and into the formation 14. The expansion of the body 26 b still ensures a significant impediment to the fracturing fluid flowing in that perforation 22 and tends to divert the fluid to other less restricted perforations 22. Shape memory materials may be those that respond to temperature or to a particular fluid exposure, etc. Alternatively, it may be that the materials are swellable materials providing the porosity and permeability noted above are maintained.

Also unique to the disclosure hereof is the porosity of the body 26 having the range as noted above. The particular porosity and permeability facilitates the diversion since at high pressure, the fluid will find a different path but at the lower pressures of production, the fluid flows through the body 26 essentially unimpeded. In addition, sand from the formation is excluded by the body 26 and hence cleanouts of the well are reduced. Diverters of the prior art offer no such screening while producing characteristics.

As to dimensions of the body 26, it is to be appreciated that nearly any geometric shape may be used with appropriate dimensions such that the body 26 is inclined to enter the perforation and then become jammed therein or radially outwardly thereof. In some embodiments the body 26 will be spherical or spheroidal (such as an oblate spheroid or prolate spheroid) while in other embodiments, the shape may be snake-like, or cubic or pyramidal, etc. In each case, the dimensions of the body 26 will be slightly larger than the dimensions of the perforation so that the high-pressure fluid will force the body 26 into the perforation and it will become jammed therein. For example, for a perforation whose nominal opening is 0.4 inches, an exemplary set of dimensions for a body 26 are 0.5 inch. This is only by way of example and no limitation is intended other than to understand the point for entry into the perforation and the tendency to jam therein.

Set forth below are some embodiments of the foregoing disclosure:

Embodiment 1: A fracture diverter including a body having a porosity and permeability that allows the passage of fluid and not proppant and a set of dimensions selected to enter an expected dimension perforation.

Embodiment 2: The diverter as in any prior embodiment, wherein the set of dimensions defines a sphere or spheroid geometric shape.

Embodiment 3: The diverter as in any prior embodiment, wherein the body comprises a shape memory property.

Embodiment 4: The diverter as in any prior embodiment, wherein the body comprises a swellable material.

Embodiment 5: The diverter as in any prior embodiment, wherein the body comprises a resilient material.

Embodiment 6: The diverter as in any prior embodiment, wherein the shape memory property is temperature based.

Embodiment 7: The diverter as in any prior embodiment, wherein the body comprises a shape memory polymer foam.

Embodiment 8: A method for fracturing a formation including pumping a diverter as in any prior embodiment into a borehole in a formation, automatically disposing a diverter body in a perforation in the borehole, and jamming the diverter body in the perforation thereby inhibiting future movement of the body in an opposite direction through the perforation.

Embodiment 9: The method as in any prior embodiment, wherein the pumping is with a fracture fluid.

Embodiment 10: The method as in any prior embodiment, wherein the automatically disposing is by the body following a path of least resistance for the fluid.

Embodiment 11: The method as in any prior embodiment, wherein the jamming is physically jamming the body into the perforation by fluid pressure.

Embodiment 12: The method as in any prior embodiment, wherein the fluid pressure associated with the jamming is higher than a flowback pressure from the formation.

Embodiment 13: The method as in any prior embodiment, wherein the jamming is by expanding a set of dimensions of the body.

Embodiment 14: The method as in any prior embodiment, wherein the expanding occurs within the perforation.

Embodiment 15: The method as in any prior embodiment, wherein the expanding occurs radially outwardly the perforation.

Embodiment 16: The method as in any prior embodiment, wherein the expanding is by shape memory.

Embodiment 17: The method as in any prior embodiment, wherein the method further comprises producing fluid from the formation through the body.

Embodiment 18: The method as in any prior embodiment, wherein the method further comprises diverting fracture fluid to perforations other than the perforation in which the body is jammed.

Embodiment 19: The method as in any prior embodiment, wherein the method further comprises automatically disposing additional bodies in additional perforations as a path of least resistance for the fluid is established in the additional perforations.

Embodiment 20: A wellbore system including a borehole in a subsurface formation, a string in the borehole having a perforation therein, and a fracture diverter as in any prior embodiment disposed in the wellbore system.

The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “about”, “substantially” and “generally” are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” and/or “substantially” and/or “generally” can include a range of ±8% or 5%, or 2% of a given value.

The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a wellbore, and/or equipment in the wellbore, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, tracers, flow improvers etc. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, etc.

While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. 

What is claimed is:
 1. A fracture diverter comprising a body having a porosity and permeability that allows the passage of fluid and not proppant and a set of dimensions selected to enter an expected dimension perforation.
 2. The diverter as claimed in claim 1 wherein the set of dimensions defines a sphere or spheroid geometric shape.
 3. The diverter as claimed in claim 1 wherein the body comprises a shape memory property.
 4. The diverter as claimed in claim 1 wherein the body comprises a swellable material.
 5. The diverter as claimed in claim 1 wherein the body comprises a resilient material.
 6. The diverter as claimed in claim 3 wherein the shape memory property is temperature based.
 7. The diverter as claimed in claim 1 wherein the body comprises a shape memory polymer foam.
 8. A method for fracturing a formation comprising: pumping a diverter as claimed in claim 1 into a borehole in a formation; automatically disposing a diverter body in a perforation in the borehole; and jamming the diverter body in the perforation thereby inhibiting future movement of the body in an opposite direction through the perforation.
 9. The method as claimed in claim 8 wherein the pumping is with a fracture fluid.
 10. The method as claimed in claim 9 wherein the automatically disposing is by the body following a path of least resistance for the fluid.
 11. The method as claimed in claim 8 wherein the jamming is physically jamming the body into the perforation by fluid pressure.
 12. The method as claimed in claim 11 wherein the fluid pressure associated with the jamming is higher than a flowback pressure from the formation.
 13. The method as claimed in claim 8 wherein the jamming is by expanding a set of dimensions of the body.
 14. The method as claimed in claim 13 wherein the expanding occurs within the perforation.
 15. The method as claimed in claim 13 wherein the expanding occurs radially outwardly the perforation.
 16. The method as claimed in claim 13 wherein the expanding is by shape memory.
 17. The method as claimed in claim 8 wherein the method further comprises producing fluid from the formation through the body.
 18. The method as claimed in claim 8 wherein the method further comprises diverting fracture fluid to perforations other than the perforation in which the body is jammed.
 19. The method as claimed in claim 8 wherein the method further comprises automatically disposing additional bodies in additional perforations as a path of least resistance for the fluid is established in the additional perforations.
 20. A wellbore system comprising: a borehole in a subsurface formation; a string in the borehole having a perforation therein; and a fracture diverter as claimed in claim 1 disposed in the wellbore system. 